1. Field of the Invention
The present invention relates to medical equipment, and particularly to medical instruments for application of staples.
The invention may prove most advantageous in surgical operations when applying sutures to various organs and soft tissues of an organism.
2. Prior Art
It is known that as far back as 1951, in different countries staples have been used in surgical operations for suturing instead of ligature filaments. This was promoted by such factors as a higher reliability of staple sutures, a decrease in the possibility of occurence of inflammatory processes along the suture line, the prime consideration consisting in simplicity and high rate of suturing with the use of staples. During last 30 years, more than one thousand patents have been granted in the leading countries for various designs of instruments for suturing with staples. Authors of these inventions aspired to reduce dimensions and weight of the instrument and at the same time to decrease unproductive time required by the surgeon to replace or recharge the surgical instrument. Detailed analysis of the prior art demonstrates that up to now this problem has not been solved satisfactorily.
In particular, there is known for a comparatively long time a surgical instrument for suturing with staples (USSR Inventor's Certificate No. 198,514), said instrument being of small dimensions and allowing extremely thin tissues and organ membranes, e.g. cornea, to be joined. The instrument functions simultaneously as a clamp and a suturing device. Its body is constructed as scissors provided with handles and jaws at the ends thereof.
One of the jaws is a clamping jaw and is provided with a socket for mounting a U-shaped staple, while the other jaw carries a female die having pits for bending the staple legs.
It is obvious that in order to apply a lengthy suture, it is necessary to repeatedly install each following staple into the socket of the clamping jaw. In spite of utilization of a special forceps-type gripping instrument, 3 to 5 minutes are required to charge such an instrument with a staple in ophthalmologic operations. It is further obvious that using such instrument for suturing e.g. walls of the stomach under conditions of gastrorrhagia, takes inadmissibly much time despite the fact that charging the instrument with a bigger staple than that used in ophthalmology is significantly simplified. The problem is not solved either by successive utilization of several above mentioned suturing devices, since frequent replacements of the instruments distract the surgeon and are undesirable in complicated operative interventions.
Many attempts have been made to eliminate the above disadvantage. For this end, surgical instruments have been developed having collecting magazines for cartridges whereto a plurality of staples are preliminarily laid (See e.g. USSR Author's Certificates and Patents Nos. 300,982; 312,024; 419,001; British Patent Specification No. 2,014,503; French Patent No. 2,416,682; FRG Patent No. 1,566,175). The bodies of said instruments are constructed in the form either of clips, or scissors. The design concept of the above suturing devices a surgical instrument disclosed in USSR Inventor's Certificate No. 415,009 as an example. This surgical instrument for application of staples comprises an elongated body provided with a hand lever (being a handle in the given instant), a female die having a pit for bending legs of staples, said female die being fastened on a distal end of said body, a clamping jaw provided with a driver for staples and mounted on said body for reciprocating travel in the direction of said female die. On the body there is also mounted a magazine having sockets for staples, said magazine being constructed in the given case as a multicharge drum.
An obvious advantage of such surgical instruments consists in that they enable applying one or several lengthy staple sutures without recharging or replacing the instrument. However, in practice the use of the above instruments is associated sometimes with a number of difficulties and undesirable postoperative effects. At present, a wide range of staples of various sizes is manufactured commercially for such instruments. At the same time, charging the magazines is carried out, as a rule, directly at the medical institutions, and sometimes even in the course of operation. The operation of charging the magazine with diminutive staples required for microsurgical operations, where the size of a staple does not exceed 1.5 mm, requires certain skills, is labor-consuming and takes much time (up to one hour). Besides, there are known cases (which are not guaranteed from their repetition in future), when the magazine was charged by mistake with one or several staples having dimensions close to those required for the given instrument, the former being designed for another special purpose surgical instrument. In some cases this resulted in jamming staples inside the magazine, at the outlet thereof or within the clamping jaw, which caused the interruption of the operation for recharging the magazine or the cartridge. In other cases, when the size of an erroneously charged staple was less than required, it remained unnoticed, however resulting afterwards in the incontinuity of the suture in the postoperative period, in the internal hemorrhages, which may be fatal. Similar negative effects were observed even when the magazine was correctly charged, but at least one staple was damaged while it was being put into the cartridge or the magazine. Such a damage is quite possible since the diameter of a wire used in the manufacture of staples in some cases does not exceed 0.1 mm.
It is also to be noted that the magazine situated close to the clamping jaw causes a substantial increase in the dimensions of the instrument and closes the operative field, thereby complicating the manipulation of the instrument in hard-to-reach places, deep wounds, and sometimes traumatizes tissues or membranes of adjacent internal organs, vessels etc. On the other hand, removal of the magazine or the cartridge from the clamping jaw toward the handlever does not solve this problem either, since it inevitably results in lengthening the path of a staple moving from the magazine toward the driver, and in increasing the possibility of jamming or deforming staples during the operation.
Still another imperfection of the prior art surgical instruments for application of staple sutures consists in their high specialization caused by strictly defined sizes of staples being applied. As it has been previously mentioned, such instruments cannot function when charged with different staples which are not designed for the use therein. For this reason, a great number of special purpose suturing devices similar to those described above, are to be kept in one operative room.
The present invention is directed to the provision of a surgical instrument for application of staples, whose design would permit, at reduced dimensions thereof, to make wire staples being only of a required size, directly when applying a suture, thereby reducing the time required for preparing the instrument, and to eliminate the possibility of errors.